Skip to main content

As U.S. warms, dangerous mosquito thrives

By Durland Fish, Mark Pagani and Anthony Leiserowitz
April 30, 2014 -- Updated 1740 GMT (0140 HKT)
The Asian Tiger mosquito carries chikungunya, a disease that originated in Africa and causes high fever and intense pain.
The Asian Tiger mosquito carries chikungunya, a disease that originated in Africa and causes high fever and intense pain.
STORY HIGHLIGHTS
  • Writers: Global warming doesn't just hurt polar bears; it can help spread disease
  • Writers: Chikungunya-carrying Asian tiger mosquito's range expands as nation warms
  • They say the illness is spreading in Caribbean and is highly likely to spread to the U.S.
  • Writers: We need to act on relationship between climate change and infectious disease

Editor's note: Durland Fish is professor of epidemiology in the Department of Epidemiology of Microbial Diseases at
Yale School of Public Health, and director of the Yale Institute of Biospheric Studies Center for EcoEpidemiology. Anthony Leiserowitz is a research scientist and director of the Yale Project on Climate Change at the School of Forestry and Environmental Studies. Mark Pagani is a professor in the Department of Geology and Geophysics and director of the Yale Climate and Energy Institute. The opinions expressed in this commentary are solely those of the authors.

(CNN) -- Many Americans think global warming is a distant risk that threatens faraway places with ice caps and polar bears. Very few Americans link global warming to infectious disease, but that could change.

Durland Fish
Durland Fish
Mark Pagani
Mark Pagani
 Anthony Leiserowitz
Anthony Leiserowitz

As the climate of the northern United States warms, the Asian tiger mosquito, one of the world's most invasive pests, continues spreading northward from Texas to New York, while extending its breeding season. These changes are happening just when chikungunya, an infectious disease carried by this and other mosquitoes, is rapidly spreading throughout the Caribbean. Pieces are falling into place for a historic epidemic on U.S. shores.

If that happens, then mosquitoes might just shift the debate from whether climate change is happening to a more serious discussion on how to respond to the consequences of a warmer world.

Studies by the Yale Project on Climate Change Communication have found that when Americans are informed about the broad health consequences of climate change, they are more likely to engage with the issue. When what's threatened are our neighbors, rather than far away polar bears, the perception of climate change is likely to shift.

When informed about the broad health consequences of climate change, participants surveyed by the Yale Project for Climate Change Communication are more likely to engage with climate issues. In the end, disease-carrying mosquitoes don't care if you are a Democrat or a Republican.

Asian tiger mosquitoes are opportunistic; they breed nearly anywhere. Unlike most other mosquitoes, they bite all day long. Nor do they mind having their blood meal interrupted by an attempted swatting. They just fly off to other victims and increase the odds of spreading disease.

"In the end, disease-carrying mosquitos don't care if you are Democrat or Republican."
Durland Fish

Arriving in Texas in the mid-1980s, Asian tiger mosquitoes spread northward to their ecological limit where annual average temperatures are 50 degrees Fahrenheit or warmer — a boundary that runs more or less through New York City. Indeed, New York health officials are monitoring Asian tiger mosquitoes in 61 locations across the city's five boroughs. The mosquito is abundant in the Washington, D.C., area.

The Asian tiger mosquito is also adapting its behavior and is able to ignore the onset of autumn, postpone hibernation, and extend its egg-laying season. More time to breed allows more Asian tiger mosquitoes in northern latitudes, just as one of the worst diseases they can carry arrived near U.S. shores.

News reports on chikungunya picked up their pace last December when the disease first appeared on the Caribbean island of St. Martin. We know it originated in East Africa, how the Makonde people in Africa named it for the contorted posture related to its painful arthritis-like symptoms, that the number of confirmed or suspected cases in the Caribbean has passed 25,000, and that it is highly likely to spread to the U.S. mainland. There is little or no discussion of the virus' propensity to mutate.

Although the outbreak is driven by the yellow fever mosquito, which thrives only in the tropics, recent mutations allow the chikungunya virus to be carried 100 times more efficiently by the Asian tiger mosquito.

Study: Beer drinkers attract mosquitoes
Mosquito season, fight the bite

This new virus strain infected hundreds of thousands of people on Reunion Island in the Indian Ocean in 2005; about 255,000 cases were reported. Many died and thousands experienced high fever and intense physical pain. The same strain has caused at least five outbreaks in Asia affecting millions, with smaller outbreaks in France and Italy.

Unfortunately, just when public health officials should be preparing for a chikungunya outbreak in the United States, the federal budget sequestration reduced funding for research on all infectious diseases. Global warming is enabling the Asian tiger mosquito to spread northward, yet climate policy remains stalled in Congress, where some elected officials still dismiss even the reality of the measurable rise in global temperatures since the Industrial Revolution.

The relationship between climate change and infectious disease needs to be a focus of the nation's strategy for outbreak prevention, preparedness, detection and response. Public understanding of chikungunya and the broader links between rising temperatures and human health could help change public discourse.

Since the first outbreak of Lyme in Connecticut, the disease has already spread into Canada. cryptococcosis, a frequently lethal fungal disease formerly restricted to the tropics, was identified in the Pacific Northwest in 2007. Valley fever and hantavirus are also spreading. All have been associated with changing environmental conditions as temperatures increase. Do we really need to wait until chikungunya arrives in the United States before we initiate responsible climate and human health policies?

Follow us on Twitter @CNNOpinion.

Join us on Facebook.com/CNNOpinion.

ADVERTISEMENT
Part of complete coverage on
November 24, 2014 -- Updated 2310 GMT (0710 HKT)
If Obama thinks pushing out Hagel will be seen as the housecleaning many have eyed for his national security process, he'll be disappointed, says David Rothkopf.
November 25, 2014 -- Updated 1311 GMT (2111 HKT)
The decision by the St. Louis County prosecuting attorney to announce the Ferguson grand jury decision at night was dangerous, says Jeff Toobin.
November 25, 2014 -- Updated 0857 GMT (1657 HKT)
China's influence in Latin America is nothing new. Beijing has a voracious appetite for natural resources and deep pockets, says Frida Ghitis.
November 24, 2014 -- Updated 2151 GMT (0551 HKT)
Iranian President Hassan Rouhani speaks during a press conference in the capital Tehran on June 14, 2014.
The decision to extend the deadline for talks over Iran's nuclear program doesn't change Tehran's dubious history on the issue, writes Michael Rubin.
November 21, 2014 -- Updated 1925 GMT (0325 HKT)
Maria Cardona says Republicans should appreciate President Obama's executive action on immigration.
November 21, 2014 -- Updated 1244 GMT (2044 HKT)
Van Jones says the Hunger Games is a more sweeping critique of wealth inequality than Elizabeth Warren's speech.
November 20, 2014 -- Updated 2329 GMT (0729 HKT)
obama immigration
David Gergen: It's deeply troubling to grant legal safe haven to unauthorized immigrants by executive order.
November 21, 2014 -- Updated 0134 GMT (0934 HKT)
Charles Kaiser recalls a four-hour lunch that offered insight into the famed director's genius.
November 20, 2014 -- Updated 2012 GMT (0412 HKT)
The plan by President Obama to provide legal status to millions of undocumented adults living in the U.S. leaves Republicans in a political quandary.
November 21, 2014 -- Updated 0313 GMT (1113 HKT)
Despite criticism from those on the right, Obama's expected immigration plans won't make much difference to deportation numbers, says Ruben Navarette.
November 21, 2014 -- Updated 0121 GMT (0921 HKT)
As new information and accusers against Bill Cosby are brought to light, we are reminded of an unshakable feature of American life: rape culture.
November 20, 2014 -- Updated 2256 GMT (0656 HKT)
When black people protest against police violence in Ferguson, Missouri, they're thought of as a "mob."
November 19, 2014 -- Updated 2011 GMT (0411 HKT)
Lost in much of the coverage of ISIS brutality is how successful the group has been at attracting other groups, says Peter Bergen.
November 19, 2014 -- Updated 1345 GMT (2145 HKT)
Do recent developments mean that full legalization of pot is inevitable? Not necessarily, but one would hope so, says Jeffrey Miron.
November 19, 2014 -- Updated 1319 GMT (2119 HKT)
We don't know what Bill Cosby did or did not do, but these allegations should not be easily dismissed, says Leslie Morgan Steiner.
November 19, 2014 -- Updated 1519 GMT (2319 HKT)
Does Palestinian leader Mahmoud Abbas have the influence to bring stability to Jerusalem?
November 19, 2014 -- Updated 1759 GMT (0159 HKT)
Even though there are far fewer people being stopped, does continued use of "broken windows" strategy mean minorities are still the target of undue police enforcement?
November 18, 2014 -- Updated 0258 GMT (1058 HKT)
The truth is, we ran away from the best progressive persuasion voice in our times because the ghost of our country's original sin still haunts us, writes Cornell Belcher.
November 18, 2014 -- Updated 2141 GMT (0541 HKT)
Children living in the Syrian city of Aleppo watch the sky. Not for signs of winter's approach, although the cold winds are already blowing, but for barrel bombs.
November 17, 2014 -- Updated 1321 GMT (2121 HKT)
We're stuck in a kind of Middle East Bermuda Triangle where messy outcomes are more likely than neat solutions, says Aaron David Miller.
November 17, 2014 -- Updated 1216 GMT (2016 HKT)
In the midst of the fight against Islamist rebels seeking to turn the clock back, a Kurdish region in Syria has approved a law ordering equality for women. Take that, ISIS!
November 17, 2014 -- Updated 0407 GMT (1207 HKT)
Ruben Navarrette says President Obama would be justified in acting on his own to limit deportations
ADVERTISEMENT